1. Field
The presently disclosed subject matter relates generally to surgical instrumentation devices, systems, and related methods, and more specifically to a spinal rod persuader device, system and method for use in placing, rearranging, and/or implanting a spinal rod adjacent to vertebrae of a spinal column.
2. Description of the Related Art
In order to stabilize the vertebrae of the spine, medical professionals have typically attached a stabilization rod along the spinal column using a series of pedicle screws attached to vertebrae. Each of the pedicle screws has a threaded portion and a head portion, with the threaded portion including screw threads that can grip each separate vertebrae. The head of the pedicle screw can include a saddle or U-shaped opening into which the spinal rod can be located. Also, set screws can be used to lock the spinal rod into the saddle or U-shaped portion of each of the pedicle screws.
During implantation or other manipulation of the spinal rod and system, a rod persuader is commonly used to persuade the spinal rod into position in the opening in the head of each pedicle screw. In general, alignment of the rod into each of the series of pedicle screws can be difficult to accomplish due to space requirements, variation in alignment of the pedicle screws, and the amount of force required to manipulate and/or bend the spinal rod. Thus, once a spinal rod is in the vicinity of a pedicle screw, a rod persuader has generally been used to simultaneously attach to both the pedicle screw and the spinal rod to urge the spinal rod into a final position within the head of the pedicle screw.
In one known device, the persuader is configured as a trigger operated device in which a distal end of a tube of the persuader is secured to the pedicle screw by a hook or claw that is simply engaged underneath the head or tulip portion of the pedicle screw. Once secured, a push rod is moved downward through the tube by action of a trigger mechanism. The push rod then engages the spinal rod to seat the spinal rod in the pedicle screw. In other devices, both the securing operation and the pushing operation of the persuader can be accomplished by a trigger mechanism. In particular, pulling the trigger a first distance causes gripper portions to engage a side of a pedicle screw. Further motion of the trigger then causes a push rod to engage the spinal rod to seat the spinal rod in the pedicle screw. Finally, another conventional rod persuader device includes first and second screw structures that are operated to both engage a pedicle screw and then to push a spinal rod into place. The conventional rod persuader device typically includes three concentric tubes that all move relative to each other by operation of screw thread mechanisms.